U.S. patent number 9,513,567 [Application Number 14/363,489] was granted by the patent office on 2016-12-06 for exposure apparatus and exposure method.
This patent grant is currently assigned to National Institute of Advanced Industrial Science and Technology. The grantee listed for this patent is National Institute of Advanced Industrial Science and Technology. Invention is credited to Shiro Hara, Yoshiki Inuzuka, Sommawan Khumpuang, Yasuaki Yokoyama.
United States Patent |
9,513,567 |
Hara , et al. |
December 6, 2016 |
Exposure apparatus and exposure method
Abstract
To provide a mask aligner that can appropriately manage very
small-quantity production and multiproduct production. The present
invention is a mask aligner 1 that exposes a wafer W in a
predetermined size through a mask M, and has a configuration that
includes: a conveying device 5 for conveying the wafer W and the
mask M; an exposure stage 3f on which the wafer W conveyed by the
conveying device 5 is installed; a mask holder 3b that is mounted
to face the exposure stage 3f and on which the mask M conveyed by
the conveying device 5 is installed; and an LED light source 8c
mounted to face the exposure stage 3f via the mask holder 3b.
Inventors: |
Hara; Shiro (Ushiku,
JP), Khumpuang; Sommawan (Tsukuba, JP),
Inuzuka; Yoshiki (Shizuoka, JP), Yokoyama;
Yasuaki (Tokyo, JP) |
Applicant: |
Name |
City |
State |
Country |
Type |
National Institute of Advanced Industrial Science and
Technology |
Chiyoda-ku, Tokyo |
N/A |
JP |
|
|
Assignee: |
National Institute of Advanced
Industrial Science and Technology (Tokyo, JP)
|
Family
ID: |
48574256 |
Appl.
No.: |
14/363,489 |
Filed: |
December 4, 2012 |
PCT
Filed: |
December 04, 2012 |
PCT No.: |
PCT/JP2012/081413 |
371(c)(1),(2),(4) Date: |
June 06, 2014 |
PCT
Pub. No.: |
WO2013/084898 |
PCT
Pub. Date: |
June 13, 2013 |
Prior Publication Data
|
|
|
|
Document
Identifier |
Publication Date |
|
US 20140320840 A1 |
Oct 30, 2014 |
|
Foreign Application Priority Data
|
|
|
|
|
Dec 6, 2011 [JP] |
|
|
2011-267030 |
|
Current U.S.
Class: |
1/1 |
Current CPC
Class: |
H01L
21/67796 (20130101); H01L 21/677 (20130101); G03F
7/2051 (20130101); H01L 21/67733 (20130101); H01L
21/67736 (20130101); G03F 7/70716 (20130101); G03F
7/70733 (20130101) |
Current International
Class: |
G03B
27/58 (20060101); G03F 7/20 (20060101); H01L
21/677 (20060101) |
References Cited
[Referenced By]
U.S. Patent Documents
Foreign Patent Documents
|
|
|
|
|
|
|
7-270123 |
|
Oct 1995 |
|
JP |
|
2000-91401 |
|
Mar 2000 |
|
JP |
|
2000-311850 |
|
Nov 2000 |
|
JP |
|
2001-237167 |
|
Aug 2001 |
|
JP |
|
Other References
Corresponding International Search Report dated Mar. 12, 2013 with
English Translation (three (3) pages). cited by applicant.
|
Primary Examiner: Persaud; Deoram
Attorney, Agent or Firm: Crowell & Moring LLP
Claims
The invention claimed is:
1. An exposure apparatus for exposing a wafer in a predetermined
size through a mask having a same size as a size of the wafer,
comprising: a shared conveying device configured to convey the
wafer and the mask; an exposure stage on which the wafer conveyed
by the conveying device is to be installed; a mask holder mounted
to face the exposure stage, the mask conveyed by the conveying
device being to be installed on the mask holder; and an exposure
light source mounted to face the exposure stage via the mask
holder, wherein the conveying device is configured to convey the
wafer and the mask to between the exposure stage and the mask
holder.
2. The exposure apparatus according to claim 1, further comprising
a front chamber that includes an installation port for installing
the wafer and the mask to be conveyed by the conveying device,
wherein the conveying device is configured to convey the wafer and
the mask installed on the installation port of the front chamber to
between the exposure stage and the mask holder.
3. A semiconductor manufacturing system, comprising the exposure
apparatus according to claim 2, wherein the mask and the wafer have
the same size, and conveyance of the mask and conveyance of the
wafer are performed by one conveyance system between
apparatuses.
4. An exposure method, comprising: a mask carry-in step of:
conveying a mask by the conveying device of the exposure apparatus
according to claim 2; and installing the mask on a side facing the
exposure stage in the mask holder; a wafer carry-in step of:
conveying a wafer by the conveying device; and installing the wafer
on a side facing the mask holder in the exposure stage; an exposure
process of causing irradiation of a light from the exposure light
source to expose the wafer through the mask; a wafer carry-out
process of conveying the wafer by the conveying device to carry out
the wafer from the exposure stage; and a mask carry-out process of
conveying the mask by the conveying device to carry out the mask
from the mask holder.
5. A semiconductor manufacturing system, comprising the exposure
apparatus according to claim 1, wherein the mask and the wafer have
the same size, and conveyance of the mask and conveyance of the
wafer are performed by one conveyance system between
apparatuses.
6. An exposure method, comprising: a mask carry-in step of:
conveying a mask by the conveying device of the exposure apparatus
according to claim 1; and installing the mask on a side facing the
exposure stage in the mask holder; a wafer carry-in step of:
conveying a wafer by the conveying device; and installing the wafer
on a side facing the mask holder in the exposure stage; an exposure
process of causing irradiation of a light from the exposure light
source to expose the wafer through the mask; a wafer carry-out
process of conveying the wafer by the conveying device to carry out
the wafer from the exposure stage; and a mask carry-out process of
conveying the mask by the conveying device to carry out the mask
from the mask holder.
7. The exposure method according to claim 6, wherein the mask
carry-in step includes conveying the mask installed on the
installation port of the front chamber by the conveying device, the
wafer carry-in step includes conveying the wafer installed on the
installation port of the front chamber by the conveying device, the
wafer carry-out process includes conveying the wafer from the
exposure stage to the installation port of the front chamber, and
the mask carry-out process includes conveying the mask from the
mask holder to the installation port of the front chamber.
8. The exposure method according to claim 7, wherein the exposure
process includes exposing the wafer through the mask in a state
where the wafer is laminated on the mask.
9. The exposure method according to claim 6, wherein the exposure
process includes exposing the wafer through the mask in a state
where the wafer is laminated on the mask.
10. The exposure apparatus according to claim 1, wherein the mask
holder including a mask suction fixing mechanism that is configured
to position and fix the mask to be installed in an inferior surface
of the mask holder on the inferior surface of the mask holder.
11. The exposure apparatus according to claim 1, wherein the
exposure stage including a wafer suction fixing mechanism that is
configured to position and fix the wafer to be installed in a top
surface of the exposure stage on the top surface of the exposure
stage.
Description
TECHNICAL FIELD
The present invention relates to an exposure apparatus and an
exposure method that expose a wafer through a mask.
BACKGROUND ART
In recent years, the manufacturing line for semiconductor devices
in which this type of exposure apparatus is used includes a
plurality of units called bays in which treatment apparatuses with
the same type of functions are brought together within a vast clean
room. A layout that employs a job-shop system has become
mainstream. In the job-shop system, the bays are coupled together
by a transfer robot and a belt conveyer.
As the workpiece treated in that manufacturing line, a wafer with a
large diameter of, for example, 12 inches is used. In the
production system, thousands of semiconductor chips are
manufactured from one wafer.
However, with this job-shop system, in the case where a plurality
of similar treatment processes are repeated, the conveyance
distance within the bay or the conveyance distance between bays
significantly increase in length, and the wait time increases.
Thus, the manufacturing time increases. This causes a cost
increase, for example, causes an increase in work in process.
Therefore, the low productivity may become a problem as a
manufacturing line for mass production of the workpieces.
Therefore, instead of the conventional manufacturing line in the
job-shop system, a manufacturing line in a flow-shop system is also
proposed. In this manufacturing line, semiconductor treatment
apparatuses are arranged in the order corresponding to the
treatment processes.
While this manufacturing line in the flow-shop system is optimal
for manufacturing singular products in large quantities, it is
necessary to rearrange the installation of the respective
semiconductor treatment apparatuses in the manufacturing line in
the order corresponding to the treatment flow of the workpiece in
the case where the manufacturing procedure (recipe) needs to be
changed due to a change of products. However, this rearrangement
every time the products are changed is not realistic considering
labor and time for the rearrangement. Especially, under the
circumstances in which huge semiconductor treatment apparatuses are
fixedly disposed within the closed space that is the clean room, it
is realistically impossible to rearrange the semiconductor
treatment apparatuses each time.
There is the need for manufacturing semiconductor in very small
quantities, for example, several pieces to several hundreds of
pieces in a manufacturing unit for engineer samples or ubiquitous
sensors. However, in a huge manufacturing line in the b-shop system
or the flow-shop system described above, manufacturing
semiconductor in very small quantities extremely reduces the cost
performance. Therefore, other kinds of products need to be
manufactured in that manufacturing line.
However, when a wide variety of products are input at the same time
for mixed production in that manner, the productivity of the
manufacturing line further decreases with increasing number of
types of products. As a result, in this huge manufacturing line,
very small-quantity production and multiproduct production cannot
be appropriately managed.
As the exposure apparatus used for this type of manufacturing line,
Patent Literature 1 discloses a conventional technique that exposes
a plurality of wafers without replacing the mask. In this Patent
Literature 1, while replacing the patterns of a plurality of masks
installed in a predetermined chamber, the configuration exposes one
wafer (substrate) to be conveyed to the inside of this chamber by
transferring several times.
CITATION LIST
Patent Literature
PATENT LITERATURE 1: Japanese Unexamined Patent Application
Publication No. 2001-237167
SUMMARY OF INVENTION
Technical Problem
However, in the conventional technique disclosed in above-described
Patent Literature 1, the wafer is exposed using the plurality of
masks installed within the chamber. For use in semiconductor
manufacture in very small quantities, for example, several pieces
to several hundreds of pieces in a manufacturing unit, the
plurality of masks installed within the chamber needs to be
replaced every time the types of semiconductor products to be
manufactured are changed by disassembling the exposure apparatus or
similar method. Accordingly, the cost performance might be
extremely reduced. Therefore, it is not easy to appropriately
manage very small-quantity production and multiproduct
production.
Generally, the mask and the wafer are different in shape.
Accordingly, completely different two conveyance mechanisms are
disposed inside of the exposure apparatus. Therefore, respective
doorways for the mask and the wafer to the exposure apparatus are
disposed. Furthermore, since these mask and wafer are different in
shape, the shape of the container for housing the mask or wafer and
the position of the doorway are also different for the mask and the
wafer. Accordingly, the conveyance path between apparatuses and the
mechanism for conveyance between apparatuses are also completely
separated for the mask and the wafer. As a result, a
microfabricated system that includes an exposure apparatus in a
mask system includes respective separate conveyance systems for the
mask and the wafer inside and outside of the apparatus. This
results in a problem of complexity and high cost due to necessity
of two similar mechanisms.
Furthermore, these mask and wafer are used for exposure as one set.
Therefore, a specific mask needs to be combined with a specific
wafer. Accordingly, the conveyance system of the mask and the
conveyance system of the wafer need two accurate control systems
for accurately combining the mask and the wafer passing through
respective different conveyance paths. Originally, the current
microfabricated system becomes enlarged due to the wafer conveyance
system alone and further needs to ensure synchronization with the
control of the mask. Thus, the complexity and the enlargement have
become significant problems.
Especially, when the variety of products becomes wider and the
quantity of products becomes smaller, the mask needs to be
carefully and quickly changed. This causes an increase of bugs in
the system, an increase in cost, and an enormous reduction in
manufacturing speed.
The present invention has been made in view of the actual situation
in the above-described conventional technique, and its object is to
provide an exposure apparatus and an exposure method that
appropriately manage very small-quantity production and
multiproduct production.
Solution to Problem
In order to achieve the objects described above, the present
invention is an exposure apparatus for exposing a wafer in a
predetermined size through a mask. The exposure apparatus includes
a conveying device, an exposure stage, a mask holder, and an
exposure light source. The conveying device is configured to convey
the wafer and the mask. On the exposure stage, the wafer conveyed
by the conveying device is to be installed. The mask holder is
mounted to face the exposure stage. The mask conveyed by the
conveying device is to be installed on the mask holder. The
exposure light source is mounted to face the exposure stage via the
mask holder.
With the present invention thus configured, the mask is conveyed by
the conveying device so as to be installed on the mask holder.
Additionally, the wafer is conveyed by the conveying device to be
installed on the exposure stage. In this state, irradiation of the
light from the exposure light source allows exposing the wafer
through the mask. That is, the configuration conveys the mask for
exposing the wafer to the mask holder using the conveying device
that conveys the wafer to the exposure stage. Accordingly, these
wafer and mask can be changed every exposure. This can facilitate
replacing or selecting the mask corresponding to the wafer to be
exposed. This allows appropriately managing very small-quantity
production and multiproduct production.
Additionally, in order to achieve the objects described above, the
present invention is the exposure apparatus that includes a front
chamber. The front chamber includes an installation port for
installing the wafer and the mask to be conveyed by the conveying
device. The conveying device is configured to convey the wafer and
the mask installed on the installation port of the front chamber to
between the exposure stage and the mask holder.
With the present invention thus configured, the wafer installed on
the installation port of the front chamber is conveyed to between
the exposure stage and the mask holder by the conveying device so
as to be installed on the exposure stage. The mask installed on the
installation port of the front chamber is conveyed to between the
exposure stage and the mask holder by the conveying device to be
installed on the mask holder. This ensures a short conveyance path
of the conveying device during conveyance of these wafer and mask,
thus allowing more appropriate exposure treatment in a shorter
period.
Additionally, in order to achieve the objects described above, the
present invention is a semiconductor manufacturing system that
includes the exposure apparatus. The mask and the wafer have the
same size. Conveyance of the mask and conveyance of the wafer are
performed by one conveyance system between apparatuses.
With the present invention thus configured, the mask and the wafer
have the same size. The conveyance of the mask and the conveyance
of the wafer are performed by one conveyance system between
apparatuses. This ensures a simple system and a faster response,
and reduces the occurrence of bugs.
Additionally, in order to achieve the objects described above, the
present invention is an exposure method that includes a mask
carry-in step, a wafer carry-in step, an exposure process, a wafer
carry-out process, and a mask carry-out process. The mask carry-in
step conveys a mask by the conveying device of the exposure
apparatus and installs the mask on a side facing the exposure stage
in the mask holder. The wafer carry-in step conveys a wafer by the
conveying device and installs the wafer on a side facing the mask
holder in the exposure stage. The exposure process causes
irradiation of a light from the exposure light source to expose the
wafer through the mask. The wafer carry-out process conveys the
wafer by the conveying device to carry out the wafer from the
exposure stage. The mask carry-out process conveys the mask by the
conveying device to carry out the mask from the mask holder.
With the present invention thus configured, the mask is conveyed by
the conveying device to install the mask on the side facing the
exposure stage in the mask holder. Subsequently, the wafer is
conveyed by the conveying device to install the wafer on the side
facing the mask holder in the exposure stage. In this state, the
light is irradiated from the exposure light source so as to expose
the wafer through the mask. Subsequently, the wafer is conveyed by
the conveying device and carried out from the exposure stage.
Subsequently, the mask is conveyed by the conveying device and
carried out from the mask holder in the configuration. As a result,
the conveying device that conveys the wafer to the exposure stage
can be used to convey the mask for exposing the wafer to the mask
holder. Accordingly, this can facilitate replacing or selecting the
mask corresponding to the wafer to be exposed, thus facilitating
the conveyance and the installation of these wafer and mask. This
allows appropriately managing very small-quantity production and
multiproduct production.
Additionally, in order to achieve the objects described above, the
present invention is the exposure method. The mask carry-in step
includes conveying the mask installed on the installation port of
the front chamber by the conveying device. The wafer carry-in step
includes conveying the wafer installed on the installation port of
the front chamber by the conveying device. The wafer carry-out
process includes conveying the wafer from the exposure stage to the
installation port of the front chamber. The mask carry-out process
includes conveying the mask from the mask holder to the
installation port of the front chamber.
With the present invention thus configured, in the mask carry-in
step and the wafer carry-in step, the mask and the wafer installed
on the installation port of the front chamber are conveyed by the
conveying device. In the wafer carry-out process, the wafer is
conveyed from the exposure stage to the installation port of the
front chamber. In the mask carry-out process, the mask is conveyed
from the mask holder to the installation port of the front chamber.
This ensures approximately the same conveyance path of the
conveying device during conveyance of these wafer and mask and a
shorter conveyance path for these wafer and mask, thus allowing
more appropriate exposure treatment in a shorter period.
Additionally, in order to achieve the objects described above, the
present invention is the exposure method. The exposure process
includes exposing the wafer through the mask in a state where the
wafer is laminated on the mask.
With the present invention thus configured, in a state where the
wafer is laminated on the mask, the wafer is exposed through the
mask. This can ensure approximately the same size of the mask as
the size of the wafer and downsize the mask, thus allowing more
appropriately managing very small-quantity production and
multiproduct production.
Advantageous Effects of Invention
With the present invention, the mask is conveyed by the conveying
device so as to be installed on the mask holder. Additionally, the
wafer is conveyed by the conveying device to be installed on the
exposure stage. Subsequently, irradiation of the light from the
exposure light source allows exposing the wafer through the mask.
That is, the configuration conveys the mask for exposing the wafer
to the mask holder using the conveying device that conveys the
wafer. Accordingly, these wafer and mask can be changed every
exposure. This can facilitate replacing or selecting the mask
corresponding to the wafer to be exposed. This allows appropriately
managing very small-quantity production and multiproduct
production.
BRIEF DESCRIPTION OF DRAWINGS
FIG. 1 is a front view illustrating an exposure apparatus according
to one embodiment of the present invention.
FIG. 2 is a right side view illustrating the above-described
exposure apparatus.
FIG. 3 is a left-front side perspective view illustrating an
exposure unit of the above-described exposure apparatus.
FIG. 4 is a right-back side perspective view illustrating the
above-described exposure unit.
FIG. 5 is a schematic explanatory view illustrating the
above-described exposure unit.
FIG. 6 is a schematic cross-sectional view illustrating a state
where a conveyance container is installed on a front chamber of the
above-described exposure apparatus.
FIG. 7 is a schematic cross-sectional view illustrating a state
where the conveyance container installed on the front chamber of
the above-described exposure apparatus is opened.
FIG. 8 includes schematic explanatory views each illustrating a
part of the above-described exposure apparatus, FIG. 8(A) is a plan
view, and FIG. 8(B) is a side view.
FIG. 9 is a schematic explanatory view illustrating a part of an
exposure light source of the above-described exposure
apparatus.
FIG. 10 is a schematic cross-sectional explanatory view
illustrating a semiconductor manufacturing system that includes the
above-describe exposure apparatus.
DESCRIPTION OF EMBODIMENTS
The following describes an exemplary embodiment of the present
invention by referring to the accompanying drawings.
FIG. 1 is a front view illustrating an exposure apparatus according
to one embodiment of the present invention. FIG. 2 is a right side
view illustrating the exposure apparatus. FIG. 3 is a left-front
side perspective view illustrating an exposure unit of the exposure
apparatus. FIG. 4 is a right-back side perspective view
illustrating the exposure unit. Additionally, FIG. 5 is a schematic
explanatory view illustrating the exposure unit. FIG. 6 is a
schematic cross-sectional view illustrating a state where a
conveyance container is installed in a front chamber of the
exposure apparatus. FIG. 7 is a schematic cross-sectional view
illustrating a state where the conveyance container installed in
the front chamber of the exposure apparatus is opened.
Additionally, FIG. 8 is a schematic explanatory view illustrating a
part of the exposure apparatus. FIG. 8(A) is a plan view. FIG. 8(B)
is a side view. FIG. 9 is a schematic cross-sectional explanatory
view illustrating a part of an exposure light source of the
exposure apparatus.
As one embodiment of the exposure apparatus according to the
present invention, the mask aligner 1 is a minimal aligner housed
in a chassis 2 with a preliminarily specified size based on a
minimal fab concept as illustrated in FIG. 1 and FIG. 2. Here, this
minimal fab concept is appropriate for a wide variety of products
in small quantities in the semiconductor manufacturing market and
can be applied to various fabs for saving resources, energy, and
investment and for ensuring high performance. The minimal fab
concept is for realizing a minimal manufacturing system that
minimalizes the production described in, for example, Japanese
patent application No. 2010-195996.
The chassis 2 of the mask aligner 1 is formed in an approximately
rectangular parallelepiped shape with a longitudinal direction
along the vertical direction. The chassis 2 has a structure that
blocks both of fine particles and gas molecules flowing to the
inside, and has a yellow room structure that blocks the entrance of
the UV light. In an apparatus upper portion 2a on the upper side of
this chassis 2, an exposure unit 3 is housed. On the lower side of
this chassis 2, an apparatus lower portion 2b is disposed. The
apparatus lower portion 2b incorporates a raw-material supplying
system for the apparatus upper portion 2a, an exhaust system, a
control unit, and similar portion.
Furthermore, in the middle portion of this apparatus upper portion
2a of the chassis 2 along the vertical direction, a depressed shape
portion is formed. The depressed shape portion has a depressed
shape on the front side of this chassis 2 from the side view. The
lower-side portion of this depressed shape portion is a front
chamber 2c for carrying a wafer W and a mask M in the chassis 2.
Approximately in the center of the top surface of this front
chamber 2c, a docking port 2d in an approximately circular shape is
disposed as a shuttle housing portion for installing a conveyance
container 4. Here, this front chamber 2c is disposed for blocking
both of fine particles and gas molecules flowing into the chassis
2. That is, this front chamber 2c is a particle lock air-tight
docking (PLAD) system for taking the wafer W or the mask M housed
in the conveyance container 4 in and out of the inside of the
chassis 2 without, for example, exposure to the external air.
Furthermore, within this front chamber 2c, a conveying device 5 is
housed. The conveying device 5 conveys the wafer W and the mask M
to be carried in from the docking port 2d to respective
predetermined positions in the exposure unit 3, and carries out the
wafer W and the mask M after being exposed by this exposure unit 3
to the docking port 2d.
Furthermore, the exposure unit 3 is housed and mounted in a wafer
process chamber 2e in the back-side upper portion of the front
chamber 2c within the chassis 2. The wafer W to be exposed by this
exposure unit 3 is formed in a disk shape with a surface as one
side surface that has a circular shape with a predetermined size,
for example, a diameter of 12.5 mm. In this wafer W, a photoresist
is formed and an alignment mark for positioning with respect to the
mask M is disposed. Here, the portion approximately at 1 mm from
the outer periphery of this wafer W is dead space that is not a
pattern area, specifically, used as a holding space for vacuum
suction. The mask M is an exposure mask in which an exposure
pattern for exposing the wafer W is preliminarily formed, and
employs a mask formed in a disk shape with the same size as the
size of the wafer W. Also, on this mask M, an alignment mark for
positioning with respect to the wafer W is disposed.
Next, the conveying device 5 employs, for example, the workpiece
conveying device disclosed in Japanese Unexamined Patent
Application Publication No. 2011-96942 or similar device. This
workpiece conveying device employs a slide-type
expansion/contraction actuator that sequentially extends and
retracts a plurality of long thin rod-shaped machine bodies to
convey a wafer or a mask held by a supporting member disposed at
the distal end of these machine bodies.
Furthermore, as illustrated in FIG. 5, the exposure unit 3 includes
a framing body 3a in a rectangular frame shape in front view. The
central portion of a flat plate-shaped plate material positioned on
the upper side of this framing body 3a is opened to form an opening
portion. On the inner side of this opening portion, a flat
plate-shaped mask holder 3b is mounted. This mask holder 3b is
mounted to face the top surface of the exposure stage 3f on a side
in which the wafer W is to be installed. The mask M is installed on
the inferior surface that is one side surface on a side facing the
wafer W to be installed on this mask holder 3b in the
configuration. In this mask holder 3b, a mask suction fixing
mechanism 3ba is disposed as mask suctioning means for positioning
and fixing the mask M to be installed in the center of the inferior
surface of this mask holder 3b on the inferior surface of this mask
holder 3b.
On the other hand, a Z-stage 3c is installed on the bottom surface
portion of the framing body 3a of the exposure unit 3. This Z-stage
3c is an XY.theta. stage with a three-dimensional adjustment
structure for adjusting each of the X direction, the Y direction,
and the inclination angle (the .theta. direction) of the exposure
stage 3f mounted on this Z-stage 3c via a load cell 3d and a level
adjustment mechanism 3e. That is, this Z-stage 3c is configured to
move the exposure stage 3f in the horizontal direction (the X
direction), move up and down this exposure stage 3f in the vertical
direction (the Y direction), and further adjust the inclination
angle (the .theta. direction) of this exposure stage 3f.
Here, this exposure stage 3f is a sample table mounted in a state
where the top surface of this exposure stage 3f faces the inferior
surface of the mask holder 3b. Furthermore, this exposure stage 3f
includes a sample suction fixing mechanism 3fa as wafer suctioning
means for suctioning and fixing the wafer W to be installed in the
center of the top surface of this exposure stage 3f on the top
surface of this exposure stage 3f so as to position and fix the
wafer W.
As illustrated in FIG. 5, the level adjustment mechanism 3e
includes a spherical-surface sliding portion Sea and a holding
portion 3eb. The spherical-surface sliding portion 3ea has the
bottom surface side formed in a spherical surface shape. The
holding portion 3eb includes a concave portion in a concave arc
surface shape for supporting the sliding surface in this spherical
surface shape of the spherical-surface sliding portion 3ea.
Furthermore, this level adjustment mechanism 3e employs an
air-cushion method in which the gas of nitrogen or similar gas is
supplied between the spherical-surface sliding portion 3ea and the
holding portion 3eb. Additionally, the level adjustment mechanism
3e is a spherical-surface sliding mechanism that can slide the
spherical-surface sliding portion 3ea with respect to the concave
portion in the arc surface shape of this holding portion 3eb so as
to adjust the angle, that is, the inclination (the .theta.
direction) of the exposure stage 3f mounted on this
spherical-surface sliding portion 3ea.
The load cell 3d is a pressure sensor that detects a force when the
Z-stage 3c moves up and down the exposure stage 3f to bring the
wafer W installed on this exposure stage 3f into contact with the
mask M installed on the inferior surface of the mask holder 3b for
positioning, so as to detect the applied pressure such as the
contact pressure of the wafer W with respect to this mask M.
Furthermore, in the exposure unit 3, as illustrated in FIG. 8b, a
three-point ball contact mechanism 3g is mounted. When the wafer W
installed on the exposure stage 3f of this exposure unit 3 and the
mask M that is suctioned and fixed to the inferior surface of the
mask holder 3b are leveled and aligned, the ball contact mechanism
3g is interposed between these wafer W and mask M. This ball
contact mechanism 3g includes a plurality of, for example, three
balls 3ga as spherical bodies. These balls 3ga are installed in
respective positions separated from one another at regular
intervals on the inferior surface of the mask holder 3b along the
circumferential direction, and are fixed and mounted on the distal
end portions of respective elongated ballbars 3gb. On the
respective base end sides of these ballbars 3gb, drive mechanisms
3gc are mounted for turning these ballbars 3gb in the horizontal
direction so as to sandwich the respective balls 3ga interposed
between the mask M and the wafer W at regular intervals on the
outer peripheral edge.
On the other hand, the conveyance container 4 is a minimal shuttle
as a sealed container for conveying the object that causes some
troubles such as contamination and reaction by being directly
exposed to the external air, that is, the wafer W and the mask M.
Specifically, this conveyance container 4 has the structure that
blocks both of fine particles and gas molecules flowing to the
inside, and has the yellow room structure that blocks the entrance
of the UV light. As illustrated in FIG. 6, this conveyance
container 4 includes a hollow disk-shaped conveyance-container main
body 4a that has an opened inferior surface. To the inferior
surface of this conveyance-container main body 4a, a container door
4b is removably mounted. The top surface of this container door 4b
has a shape on which the wafer W and the mask M can be installed.
In the state where the wafer W or the mask M is installed on the
top surface of the container door 4b, fitting this container door
4b to the inferior surface of the conveyance-container main body 4a
causes a state where the inside of this conveyance container 4 is
sealed in this configuration.
Furthermore, the docking port 2d of the front chamber 2c is an
installation port for installing the conveyance container 4 that
houses the wafer W or the mask M, and includes an apparatus door
2da fitted from the inside of this front chamber 2c as illustrated
in FIG. 7. In a state where the container door 4b faces downward,
the conveyance container 4 is fitted to this apparatus door 2da. In
this state, the apparatus door 2da is moved downward so as to move
the container door 4b downward together with the apparatus door 2da
due to, for example, the operation of the electromagnet or similar
operation. The wafer W, the mask M, or similar object installed on
this container door 4b can be conveyed to the inside of the front
chamber 2c in this configuration.
Furthermore, on the upper portion of the framing body 3a of the
exposure unit 3, a workpiece detecting camera 6, a monitoring
camera 7, and a UV irradiation unit 8 are mounted while being
arranged in a row as illustrated in FIG. 1, FIG. 3, and FIG. 4.
These workpiece detecting camera 6, monitoring camera 7, and UV
irradiation unit 8 are arranged in a row along the conveying
direction while the conveying device 5 conveys the wafer W and the
mask M, and are installed on a camera moving stage 9 that can move
along this conveying direction. On this camera moving stage 9, a
drive mechanism (not illustrated) is mounted.
Here, the workpiece detecting camera 6 detects the wafer W or the
mask M conveyed to the exposure stage 3f or the mask holder 3b, for
example, is constituted by a CCD camera and similar member. This
workpiece detecting camera 6 is an orientation-flat detecting
camera for detecting, for example, a positioning portion such as an
orientation flat preliminarily formed on the mask M.
The monitoring camera 7 is a camera for alignment, and is used for
adjusting the position of the mask M with respect to the wafer W
based on the alignment mark of the mask M and the alignment mark of
the wafer W.
Furthermore, the UV irradiation unit 8 is a UV light source output
unit that is mounted in the position facing the exposure stage 3f
via the mask holder 3b for proximity exposure of the wafer W
installed on this exposure stage 3f through the mask M installed on
the mask holder 3b. Specifically, as illustrated in FIG. 9, this UV
irradiation unit 8 includes a condenser lens column 8a as a
cylindrically-shaped light main body and a cylindrically-shaped
integrator lens column 8b mounted to be concentrically fitted to
the distal end portion of this condenser lens column 8a. On the
base end side of the inside of the condenser lens column 8a, one
UV-LED chip is mounted as an exposure light source so as to dispose
an LED light source 8c. This LED light source 8c is constituted by
a light-emitting diode that emits ultraviolet light with a short
wavelength of, for example, 365 nm corresponding to i-ray.
On the optical axis on the distal end side of the LED light source
8c in the condenser lens column 8a, a plurality, for example, four
of first to fourth condenser lenses 8d, 8e, 8f, and 8g are mounted
for condensing the ultraviolet light irradiated from this LED light
source 8c. These first to fourth condenser lenses 8d to 8g are each
constituted as a convex lens as illustrated in FIG. 9. Furthermore,
these first to fourth condenser lenses 8d to 8g are arranged in a
straight line to have respective planar portions facing the LED
light source 8c side and respective convex portions facing the
distal end side of the condenser lens column 8a, and are housed in
this condenser lens column 8a. These first to fourth condenser
lenses 8d to 8g reduce the diffusion of the ultraviolet light from
the LED light source 8c at the first condenser lens 8d, the second
condenser lens 8e, the third condenser lens 8f, and the fourth
condenser lens 8g in stages, thus efficiently condensing the
ultraviolet light irradiated from this LED light source 8c.
Furthermore, within the integrator lens column 8b, an integrator
lens 8h is housed. This integrator lens 8h is constituted by a
plurality, for example, four rod lenses 8i each in a quadrangular
prism shape formed with a cross-sectional square shape.
Furthermore, this integrator lens 8h is constituted such that
respective side surfaces of these rod lenses 8i are brought into
surface contact with one another to be squarely arranged in front
view and coupled together in a state where the respective
longitudinal directions of the four rod lenses 8i are parallel to
one another. This integrator lens 8h is installed in the position
where the ultraviolet light after passing through the fourth
condenser lens 8g enters into the respective rod lenses 8i. That
is, this integrator lens 8h totally reflects the ultraviolet light
emitted from the LED light source 8c and condensed by the first to
fourth condenser lenses 8d to 8g using the respective rod lenses 8i
of this integrator lens 8h, so as to uniform the irradiance
distribution of the ultraviolet-light irradiation plane on which
the ultraviolet lights passing through these rod lenses 8i are
irradiated. Specifically, this integrator lens 8h ensures an
irradiation range within .+-.5% on the surface of the wafer W.
Next, the following describes a semiconductor manufacturing system
that includes the exposure apparatus of one embodiment described
above.
FIG. 10 is a schematic explanatory view illustrating the
semiconductor manufacturing system that includes the exposure
apparatus. As illustrated in FIG. 10, each unit process apparatus
10 constituted by the same chassis 2 that includes the mask aligner
1 is placed on a guideway 12 formed in a rail shape to form a
semiconductor manufacturing line, thus being positioned on the same
semiconductor manufacturing line preliminarily set on the floor. In
an ordinary state, the respective unit process apparatuses 10 are
arranged on the guideway 12 in a flow-shop system in accordance
with the order of a recipe. In the arrangement example of the unit
process apparatuses 10 in FIG. 10, the unit process apparatuses 10
are regularly disposed at a predetermined interval. However, the
respective unit process apparatuses 10 may be closely arranged
without gap.
For each unit process apparatus 10, a recipe ID is recorded on the
outer surface of the unit process apparatus 10. The recipe ID is
used for identifying which single process (a process corresponding
to the recipe) in the process treatment this unit process apparatus
10 performs. In the record of this recipe ID, a radio frequency ID
(RFID) is used to facilitate contactlessly writing and reading in
association with a change of the recipe for the unit process
apparatus 10 or similar parameter.
In parallel to the guideway 12, conveyance means 14 is disposed as
a conveyance system between apparatuses for conveying conveyance
containers 4 that house masks and wafers. This conveyance means 14
can employ a mechanism ordinarily used for a semiconductor
manufacturing apparatus of a belt type, a mechanical type, or
similar type. Additionally, this conveyance means 14 is configured
to convey the conveyance container 4 between respective front
chambers 2c disposed in the unit process apparatuses 10.
Furthermore, above the semiconductor manufacturing line thus
configured, as illustrated in FIG. 10, a layout apparatus 17 is
disposed for rearranging the unit process apparatuses 10. This
layout apparatus 17 includes a guide rail 17a and a
unit-process-apparatus transporting portion 17b. The guide rail 17a
is arranged in parallel to the guideway 12. The
unit-process-apparatus transporting portion 17b moves while being
suspended from this guide rail 17a. This layout apparatus 17
includes a read mechanism for the recipe IDs of the respective unit
process apparatuses 10. The layout apparatus 17 is configured to
select the unit process apparatus 10 with a predetermined recipe ID
corresponding to a control signal from a central control unit and
cause the unit-process-apparatus transporting portion 17b to grip
and transport the selected unit process apparatus 10 so as to
rearrange the unit process apparatus 10 in a predetermined
position.
Furthermore, the layout apparatus 17 is appropriate for quickly
changing the layout of the multiple unit process apparatuses 10. On
the other hand, the facility cost of the layout apparatus 17 is
needed. Therefore, when there is no problem to spend much time on
the layout change, or for saving the facility cost on the layout
apparatus 17, the unit process apparatuses 10 may be conveyed by
humans. In this conveyance by human, casters are disposed on the
bottom portion of the unit process apparatus 10 for conveyance.
Next, the following describes an exposure method using the exposure
apparatus of one embodiment described above.
<Mask Setting Process>
Firstly, the container door 4b is removed from the
conveyance-container main body 4a of the conveyance container 4 to
set the mask M on this container door 4b. Subsequently, this
container door 4b is mounted to the conveyance-container main body
4a to set this mask M in the conveyance container 4.
<Mask Carry-In Process>
Next, in a state where this container door 4b side on which the
mask M is set in the conveyance container 4 is directed downward,
this conveyance container 4 is fitted to the docking port 2d of the
front chamber 2c of the mask aligner 1. At this time, for example,
in a manual mode or similar mode, the Z-stage 3c and the level
adjustment mechanism 3e are driven as necessary to perform the
leveling of the exposure stage 3f.
Thereafter, the apparatus door 2da of the docking port 2d of the
front chamber 2c of the mask aligner 1 is downwardly moved to
downwardly move the container door 4b of the conveyance container 4
together with this apparatus door 2da. Accordingly, the container
door 4b is removed from this conveyance container 4 so as to open
the conveyance container 4.
In this state, the height of the exposure stage 3f is adjusted by
the Z-stage 3c to move this exposure stage 3f to a mask-delivery
position set in advance. Subsequently, for example, an automatic
mode or similar mode is set. With pressing a start switch (not
illustrated) for starting the driving of the conveying device 5 or
similar operation, the mask M installed on the container door 4b is
held by the conveying device 5 and then conveyed by the
expansion/contraction actuator. Then, the mask M is installed in a
predetermined position on the exposure stage 3f of the exposure
unit 3.
Thereafter, the mask M installed on this exposure stage 3f is
vacuum-suctioned by the sample suction fixing mechanism 3fa of this
exposure stage 3f to be suctioned and fixed in the predetermined
position on this exposure stage 3f.
Subsequently, the exposure stage 3f is moved by the Z-stage 3c so
as to achieve a height within a preliminarily registered focal
length of the workpiece detecting camera 6. Then, the exposure
stage 3f is set to a wait state. In this state, for example, in the
manual mode or similar mode, the Z-stage 3c is driven as necessary
while the mask pattern of the mask M is confirmed by visual
observation using the workpiece detecting camera 6, so as to
perform position adjustment of the mask M on the exposure stage 3f
in the X direction, the Y direction, and the .theta. direction.
Subsequently, for example, in the manual mode or similar mode, this
exposure stage 3f is upwardly moved by the Z-stage 3c until the
mask M on the exposure stage 3f is brought into close contact with
the inferior surface of the mask holder 3b. In this state, the mask
M is vacuum-suctioned by the mask suction fixing mechanism 3ba of
the mask holder 3b to suction and fix the mask M in a predetermined
position on the inferior surface of this mask holder 3b.
Thereafter, suction fixing of the mask M by the sample suction
fixing mechanism 3fa of the exposure stage 3f is released, and then
this exposure stage 3f is moved to the mask-delivery position by
the Z-stage 3c.
Furthermore, for example, with a simulated carry-out operation of
the mask M or similar operation, a bring-back operation of the
conveying device 5 is performed and the apparatus door 2da of the
docking port 2d is moved upward. Accordingly, the container door 4b
is fitted to the conveyance-container main body 4a of the
conveyance container 4 fitted to this docking port 2d so as to
ensure sealing.
Subsequently, the empty conveyance container 4 that is sealed by
mounting this container door 4b is removed from the docking port 2d
of the front chamber 2c.
<Wafer Carry-In Process>
Next, the conveyance container 4 that houses the wafer W before the
exposure treatment is prepared and fitted to the docking port 2d of
the mask aligner 1 while the container door 4b side of this
conveyance container 4 is directed downward.
Thereafter, the apparatus door 2da of the docking port 2d of the
mask aligner 1 is downwardly moved to downwardly move the container
door 4b of the conveyance container 4 together with this apparatus
door 2da. Accordingly, the container door 4b is removed from this
conveyance container 4 so as to open the conveyance container
4.
In this state, for example, the automatic mode or similar mode is
set. With pressing the start switch of the conveying device 5 or
similar operation, the wafer W installed on the container door 4b
is held by the conveying device 5 and then conveyed by the
expansion/contraction actuator. Then, the wafer W is installed in a
predetermined position on the exposure stage 3f of the exposure
unit 3. At this time, the height of the exposure stage 3f is
adjusted by the Z-stage 3c to move this exposure stage 3f to a
wafer-delivery position. That is, because these mask M and wafer W
are different in mass, the amount of deflection in the longitudinal
direction of this expansion/contraction actuator is changed
corresponding to the length of a conveying stroke by the
expansion/contraction actuator of the conveying device 5. Thus, the
delivery positions of these mask M and wafer W are different from
each other.
Furthermore, the wafer W installed on the exposure stage 3f is
vacuum-suctioned by the sample suction fixing mechanism 3fa of this
exposure stage 3f to be suctioned and fixed in the predetermined
position on this exposure stage 3f. In this state, as illustrated
in FIG. 8, the drive mechanism 3gc is driven to perform a turning
operation of the respective ballbars 3gb so as to insert the
respective balls 3ga of the ball contact mechanism 3g into a ball
insertion position B between the mask M and the wafer W from a ball
standby position A. At this time, the respective balls 3ga of this
three-point ball contact mechanism 3g are set to contacting
positions in contact with the surface of the photoresist applied
over the wafer W.
Next, the alignment position of the monitoring camera 7 registered
in advance is moved. Specifically, the exposure stage 3f is
adjusted in the upward and downward directions by the Z-stage 3c to
be in the focus position, that is, in a position within the focus
depth of this monitoring camera 7.
Furthermore, for example, in the manual mode or similar mode, the
exposure stage 3f is upwardly moved by the Z-stage 3c such that the
wafer W on this exposure stage 3f approaches the mask M. At this
time, the respective balls 3ga of the ball contact mechanism 3g are
sandwiched between the photoresist on the wafer W and the mask M.
Accordingly, the mask M and the wafer W become unstable (not in a
parallel state) due to these respective balls 3ga. However, a
sliding action of the holding portion 3eb on the spherical-surface
sliding portion 3ea of the level adjustment mechanism 3e ensures
the levelness between the wafer W on the exposure stage 3f and the
mask M, thus performing leveling.
Next, in a state after three-dimensional positioning and leveling
of these wafer W and mask M, for example, in the manual mode or
similar mode, a clearance distance (alignment gap) of, for example,
30 .mu.m (any set value) from the mask M is ensured. In this state,
the monitoring camera 7 is used to set a state that allows
observing both of the alignment mark of the mask M and the
alignment mark of the wafer W at the same time.
Additionally, in this state, for example, with pressing an
operation switch (not illustrated) or similar operation, the
Z-stage 3c is driven as necessary while these alignment marks of
the mask M and the wafer W are confirmed by visual observation, so
as to perform position adjustment of the wafer W on the exposure
stage 3f in the X direction, the Y direction, and the .theta.
direction, that is, alignment (positioning).
After completion of the alignment of these mask M and wafer W, the
exposure stage 3f is downwardly moved by the Z-stage 3c.
Subsequently, the drive mechanism 3gc is driven for a turning
operation of the respective ballbars 3gb so as to move and evacuate
the respective balls 3ga of the ball contact mechanism 3g from the
ball insertion position B to the ball standby position A.
Next, the applied pressure of the wafer W with respect to the mask
M is adjusted while a pressure value to be detected by the load
cell 3d is confirmed. The exposure stage 3f is elevated so as to
bring the wafer W into close contact with the mask M until a
predetermined applied pressure is obtained.
<Exposure Process>
After these mask M and wafer W are laminated in close contact with
each other, for example, with operation of an operation switch (not
illustrated) or similar operation, the camera moving stage 9 is
moved by the drive mechanism and the UV irradiation unit 8 is moved
above these mask M and wafer W.
In this state, for example, the manual mode or similar mode is set.
Based on an irradiation time set in advance, the ultraviolet light
is emitted from the LED light source 8c of the UV irradiation unit
8. This ultraviolet light is irradiated to the wafer W through the
mask M so as to expose this wafer W.
At this time, the ultraviolet light emitted from the LED light
source 8c of the UV irradiation unit 8 is condensed after passing
through the first to fourth condenser lenses 8d to 8g in the
condenser lens column 8a. Subsequently, the ultraviolet light
passes through the integrator lens 8h in the integrator lens column
8b so as to uniform the irradiance distribution on an
ultraviolet-light irradiation plane of this ultraviolet light.
Thereafter, the ultraviolet light is irradiated to the wafer W
through the mask M.
<Wafer Carry-Out Process>
Thereafter, the exposure stage 3f is moved to the wafer-delivery
position by the Z-stage 3c. At this time, the position of the
exposure stage 3f is finely adjusted by the alignment adjustment of
the mask M and the wafer W. Accordingly, this exposure stage 3f
needs to be moved to the wafer-delivery position before this
alignment adjustment.
Next, for example, an exposure termination signal is transmitted to
perform a bring-back operation of the exposed wafer W on the
exposure stage 3f by the conveying device 5 so as to install the
wafer W on the container door 4b. Subsequently, the apparatus door
2da of the docking port 2d is moved upward to fit the container
door 4b to the conveyance-container main body 4a of the conveyance
container 4 fitted to this docking port 2d for sealing.
Subsequently, the conveyance container 4 that is sealed by mounting
this container door 4b and houses the exposed wafer W is removed
from the docking port 2d of the front chamber 2c.
<Mask Carry-Out Process>
Thereafter, the empty conveyance container 4 is prepared. The
container door 4b side of this conveyance container 4 is directed
downward to be fitted to the docking port 2d of the mask aligner 1.
In this state, the apparatus door 2da of this docking port 2d is
downwardly moved to downwardly move the container door 4b of the
conveyance container 4 together with this apparatus door 2da.
Accordingly, the container door 4b is removed from this conveyance
container 4 so as to open the conveyance container 4.
Next, for example, a mask ejection mode is set by pressing a mask
ejection switch (not illustrated) or similar operation.
Subsequently, the exposure stage 3f is upwardly moved by the
Z-stage 3c to bring the exposure stage 3f into close contact with
the mask M suctioned and fixed to the inferior surface of the mask
holder 3b. In this state, suction fixing of the mask M by the mask
suction fixing mechanism 3ba of the mask holder 3b is released.
Thereafter, the sample suction fixing mechanism 3fa of the exposure
stage 3f is driven to suction and fix the mask M onto this exposure
stage 3f, this exposure stage 3f is moved to the mask-delivery
position by the Z-stage 3c. In this state, suction fixing of the
mask M by the sample suction fixing mechanism 3fa of the exposure
stage 3f is released. Subsequently, a bring-back operation of the
mask M on this exposure stage 3f is performed by the conveying
device 5 so as to install the mask M on the container door 4b.
Subsequently, the apparatus door 2da of the docking port 2d is
moved upward to fit the container door 4b to the
conveyance-container main body 4a of the conveyance container 4
fitted to this docking port 2d for sealing. Furthermore, the
conveyance container 4 in which this container door 4b is mounted
and the mask M is housed is removed from the docking port 2d of the
front chamber 2c to carry out the mask M from the mask aligner
1.
<Operation and Effect>
As described above, in the mask aligner 1 of the one embodiment
above, the mask M and the wafer W have the same size. The same
conveyance container 4 is used for these mask M and wafer W. The
same doorway to the inside of the mask aligner 1 is used for the
mask M and the wafer W. The front chamber 2c is also one for these.
Also, the same conveying device 5 is used for conveying the mask M
and the wafer W between the wafer process chamber 2e and the front
chamber 2c. Accordingly, the machine mechanisms regarding these
members can be about half of the machine mechanisms compared with
the case where respective members for the mask M and the wafer W
are disposed independently from one another. This allows
significantly reducing the apparatus manufacturing cost, the
apparatus control cost, and the in-plant apparatus conveyance cost
and ensures simple mechanisms in the apparatus. Accordingly, the
sources of generation of the fine particles can also be reduced to
half amount. This allows improving the manufacturing yield.
Furthermore, one conveyance control system and one plant conveyance
system are enough in the mask aligner 1. This ensures a simple
system and a faster response, and reduces the occurrence of
bugs.
Furthermore, the conventional mask aligner does not ordinarily
employ the complicated mechanisms such as the conveyance of the
mask in the sealed vessel between the apparatuses and docking of
the mask conveyance container with the mask aligner. Instead, a
clean room is used for setting or taking out the mask to/from the
mask aligner by human hand. Accordingly, preparing two systems for
the mask and the wafer in the mask aligner like the conventional
mask aligner results in a high-level and complicated machine
mechanism, thus increasing the cost. In contrast, the mask aligner
1 of the present invention has one unified system for conveyance of
the wafer W and the mask M. In this respect, the clean room is not
needed. As the conveyance of these wafer W and mask M, the sealed
conveyance container 4 is used for the sealed conveyance of the
wafer W and the mask M between the mask aligner 1 and the
conveyance container 4 using the sealed docking system of the front
chamber 2c illustrated in FIG. 6 and FIG. 7. This allows completely
eliminating the need for the clean room.
Additionally, the mask M and the wafer W have the same size, and
these mask M and wafer W can be conveyed by one conveyance system
(conveying device 5). This allows manufacturing the mask M using a
wafer processing/manufacturing system itself. That is,
conventionally, the mask and the wafer have different sizes.
Naturally, a fine processing equipment for the mask and a wafer
processing equipment are different from each other. Accordingly,
these mask and wafer are manufactured in different plants.
Generally, the mask is manufactured by processes of (cleaning),
(mask material deposition such as chrome), (resist coating),
(exposure), (developing), (etching), and (resist removal) in this
order. These processes are basically a part of microfabrication
processes on the wafer. The mask aligner 1 of the present invention
can convey the mask M and the wafer W in the same manner. This
allows manufacturing both of these mask M and wafer W in one
production line. As a result, this eliminates the need for
outsourcing of the mask M or similar need. This allows
manufacturing the mask M on site in a short time as necessary, thus
significantly reducing the manufacturing cost of the mask M.
Specifically, the configuration employs the conveying device 5 that
conveys the wafer W to the exposure stage 3f to convey the mask M
for exposing this wafer W. As a result, these wafer W and mask M
can be changed every exposure. Additionally, this can facilitate
replacing and selecting the mask M corresponding to the wafer W to
be exposed. At this time, the wafer W is exposed through this mask
M in a state where the mask M is laminated on the wafer W to be
conveyed by the conveying device 5. This configuration allows
setting the same size of this mask M as the size of the wafer W and
downsizing this mask M.
In this case, forming each of these wafer W and mask M in a disk
shape with a diameter of 12.5 mm allows exposing the wafer W as a
semiconductor while changing the mask M one by one compared with a
manufacturing line using a comparatively large substrate like a
job-shop system and a flow-shop system that are conventionally
used. This configuration allows appropriately managing very
small-quantity production and multiproduct production, and is
appropriate for manufacture of semiconductor in very small
quantities. This allows manufacturing semiconductor in very small
quantities with high cost performance.
Installing the mask holder 3b facing the exposure stage 3f from
above causes the wafer W installed on the docking port 2d of the
front chamber 2c of the mask aligner 1 to be taken out from the
conveyance container 4 and conveyed to between the exposure stage
3f and the mask holder 3b by the conveying device 5 so as to be
installed on the exposure stage 3f. Furthermore, the mask M
installed on the docking port 2d is taken out from the conveyance
container 4 and conveyed to between the exposure stage 3f and the
mask holder 3b by the conveying device 5 so as to be suctioned and
fixed to the inferior surface of the mask holder 3b. Accordingly,
approximately the same and shorter length can be set for conveyance
paths of the conveying device 5 when these wafer W and mask M are
conveyed. This allows more appropriately conveying the mask M and
the wafer W in a shorter period, and allows performing exposure
treatment using these mask M and wafer W in a shorter period.
At this time, the sample suction fixing mechanism 3fa is disposed
in the exposure stage 3f. Accordingly, in a state, where the mask M
and the wafer W to be installed on this exposure stage 3f is
suctioned and fixed on this exposure stage 3f, installation
positions of these mask M and wafer W can be adjusted by the
Z-stage 3c or similar member. Additionally, the mask suction fixing
mechanism 3ba is disposed in the mask holder 3b. Accordingly, the
mask M to be brought into contact with the inferior surface of this
mask holder 3b can be suctioned and fixed to the inferior surface
of this mask holder 3b for positioning. Thus, this allows simply
and reliably positioning these mask M and wafer W with a
comparatively simple configuration.
The mask aligner 1 includes the exposure unit 3 housed in the
chassis 2. For example, a predetermined portion such as the chassis
2 and the peripheral area of the exposure unit 3 in this mask
aligner 1 is covered with a member that shields an optical
wavelength that causes the resist on the wafer W to be exposed, for
example, an ultraviolet light. This member is, for example, an
acrylic board colored in yellow. Accordingly, this mask aligner 1
itself can be used as an ultraviolet ray-shielded room what is
called a yellow room. Furthermore, in the configuration, the wafer
W and the mask M before being carried in the mask aligner 1 are
housed in the conveyance container 4. Accordingly, forming this
conveyance container 4 by an ultraviolet-ray shielding member to be
a sealed type so as to use the inside of this conveyance container
4 as a yellow room prevents the irradiation of the ultraviolet ray
to the wafer W both before being carried in the mask aligner 1 and
after being carried out. This allows eliminating the need for
housing these conveyance container 4 and mask aligner 1 in the
ultraviolet ray-shielded room (yellow room).
Furthermore, the mask aligner 1 itself is small-sized. Even in the
case where this mask aligner 1 or the conveyance container 4 itself
is not used as a yellow room, the workroom for housing these mask
aligner 1 and conveyance container 4 can be downsized. Accordingly,
the ultraviolet ray-shielded room (yellow room) can also be
downsized compared with conventional manufacturing lines in a
job-shop system and a flow-shop system.
Specifically, in a semiconductor pretreatment plant that has a
conventional manufacturing line in a job-shop system or a flow-shop
system, the apparatus installation area of groups of application
apparatuses, exposure apparatuses, and developing apparatuses to be
set in a yellow room where a light such as an ultraviolet ray is
controlled occupies approximately a quarter of the overall area for
a pretreatment process. However, similarly to the mask aligner 1 of
the present invention, in the case where the minimal fab structure
is employed for other application apparatus and developing
apparatus to be housed in the same chassis 2, the region where the
light such as a ultraviolet ray needs to be controlled can be
reduced to approximately 1/30 of the conventional
configuration.
Furthermore, the mask holder 3b is mounted to face the exposure
stage 3f. This allows three-dimensionally moving the exposure stage
3f with respect to this mask holder 3b by the Z-stage 3c and then
positioning between the wafer W installed on this exposure stage 3f
and the mask M suctioned and fixed to the inferior surface of the
mask holder 3b. Additionally, the respective balls 3ga of the ball
contact mechanism 3g are interposed between the mask M suctioned
and fixed to the inferior surface of the mask holder 3b and the
wafer W installed on the exposure stage 3f. In this state, the
exposure stage 3f is upwardly moved by the Z-stage 3c to press the
wafer W on this exposure stage 3f against the mask M via the
respective balls 3ga. Accordingly, the level adjustment mechanism
3e causes this exposure stage 3f to slide along a spherical surface
shape as necessary. This allows leveling of the wafer W with
respect to the mask M installed on the mask holder 3b.
Accordingly, the leveling and the position adjustment between these
mask M and wafer W can be performed without bringing these mask M
and wafer W into contact with each other. This allows more simply
and accurately performing positioning between these mask M and
wafer W. In a state where positioning between the exposure stage 3f
and the mask holder 3b is performed, irradiation of the ultraviolet
light from the LED light source 8c of the UV irradiation unit 8
allows exposing the wafer W installed on the exposure stage 3f
through the mask M installed on the mask holder 3b. Accordingly,
the wafer W can be accurately exposed through this mask M.
Specifically, the incomplete lithography area on the wafer W is
formed at about 0.50 mm from the outer peripheral edge and the
uniformity of the exposure amount of this wafer W becomes about
.+-.3.3%.
Furthermore, using the light-emitting diode that causes irradiation
of the ultraviolet light as the LED light source 8c of the UV
irradiation unit 8 allows exposing the wafer W through the mask M
using the ultraviolet light emitted from the LED light source 8c
with a small heat generation amount and a short start-up time until
a light with a wavelength required for the exposure is emitted.
Accordingly, the exposure process of this wafer W can be performed
in a shorter period and more reliably.
At this time, the ultraviolet light to be emitted from this LED
light source 8c is condensed by the first to fourth condenser
lenses 8d to 8g and then totally reflected by the respective rod
lenses 8i of the integrator lens 8h, so as to uniformize the
irradiation distribution on the ultraviolet-light irradiation plane
of the ultraviolet light. This allows uniformizing the irradiation
distribution of the ultraviolet ray to the surface of the wafer W
to be exposed. Thus, the surface of this wafer W can be more
accurately exposed over a wider range.
Furthermore, using the LED light source 8c that emits an
ultraviolet light of a short-wave light with a wave length of, for
example, 365 nm allows reliably and accurately exposing the wafer W
with the ultraviolet light to be emitted from this LED light source
8c. Additionally, condensing the light by the first to fourth
condenser lenses 8d to 8g and uniformizing the ultraviolet-ray
irradiation distribution by the integrator lens 8h ensure the
irradiation range within .+-.5% to the wafer W regarding the
ultraviolet light to be emitted from the LED light source 8c. This
allows exposing a range within .+-.5% of this wafer W. Accordingly,
even in the case where the mask M with a size equal to the size of
this wafer W is used, the exposure accuracy of this wafer W can be
ensured.
<Others>
Here, in the above-described one embodiment, the wafer W to be
exposed by the exposure unit 3 of the mask aligner 1 and the mask M
each have a disk shape with a diameter of 12.5 mm in the same size.
However, the present invention is not limited to this. For example,
the size of the mask M can be slightly larger than the size of the
wafer W. Alternatively, the respective sizes of these mask M and
wafer W can be larger or smaller corresponding to the size of
semiconductor to be manufactured or similar parameter.
After the balls 3ga of the ball contact mechanism 3g are interposed
between the mask M suctioned and fixed by the mask holder 3b and
the wafer W installed on the exposure stage 3f, the leveling and
the alignment between these mask M and wafer W are performed in
this configuration. However, as necessary, the configuration may
perform the leveling and the alignment between these mask M and
wafer W without interposing the respective balls 3ga of the ball
contact mechanism 3g.
Furthermore, the integrator lens 8h of the UV irradiation unit 8
has the configuration in which the four rod lenses 8i with the
cross-sectional square shapes are combined together to be squarely
arranged. For example, the integrator lens 8h may have a
configuration in which a plurality of rod lenses with cross
sections in regular hexagon shapes are combined together in a
honeycomb shape.
In the configuration, the manual mode and the automatic mode are
combined in various processing operations of the mask aligner 1. As
necessary, as a possible configuration, the mode can be switched to
the manual mode as necessary or a fully-automatic mode can be set.
In this case, after the mask M is conveyed to the mask aligner 1,
the bring-back operation of the conveying device 5 is performed by
a simulated carry-out operation of the mask M or similar operation.
The bring-back operation of this conveying device 5 can be manually
performed by generating a simulated signal of exposure completion
or can be automatically performed by programming in advance or
similar method.
REFERENCE SIGNS LIST
1 mask aligner 2 chassis 2a apparatus upper portion 2b apparatus
lower portion 2c front chamber 2d docking port 2da apparatus door
2e wafer process chamber 3 exposure unit 3a framing body 3b mask
holder 3ba mask suction fixing mechanism 3c Z-stage 3d load cell 3e
level adjustment mechanism 3ea spherical-surface sliding portion
3eb holding portion 3f exposure stage 3fa sample suction fixing
mechanism 4 conveyance container 4a conveyance-container main body
4b container door 5 conveying device 6 workpiece detecting camera 7
monitoring camera 8 UV irradiation unit 8a condenser lens column 8b
integrator lens column 8c LED light source 8d first condenser lens
8e second condenser lens 8f third condenser lens 8g fourth
condenser lens 8h integrator lens 8i rod lens 9 camera moving stage
10 unit process apparatus 12 guideway 14 conveyance means 17 layout
apparatus 17a guide rail 17b unit-process-apparatus transporting
portion A ball standby position B ball insertion position M mask W
wafer
* * * * *